chrome moly

[runt13]

i have a question about cutting chrome moly. what is best, hack / band saw or chop saw?

i use a chop saw for all my regular fabrication, but was woundering if using a chop saw would harm the chrome moly.


RUNT

[geh458]

I wouldn't think it would mater, but you would lose a tiny bit more material using a chop-saw versus a horizontal band-saw (blade width is narrower).  You'd wear yourself out using a hacksaw, but then again if that's all you have on hand....

All of the people I know that do fabrication work use a horizontal band-saw.

[johnneilson]

cutting the material shouldn't give you any issues.
Generally speaking, the "heat affected zone" is an issue with welding/temperatures.

There is lots of information on this subject, most I agree with.
Carrol Smith books, I forget, I think "Engineering to win" is a good reference point.

Personally, I have built many frames and repaired many others. Even some of the alloys from Europe respond well to the same theology as 4130.

John

PS, I use a portable band saw to cut material, if having to modify in the field a hacksaw is better than a torch.

[1212FBGS]

i use little baby chipmunks..... and being an environmentally conscious guy that i am, i recycle them into my stew pot when there little teeth are worn to the quick.....
Kent

[runt13]

thanks folks, heat was my concern. i have a nice horizontal band saw, i just happen to be in a chassis shop and saw [no pun intended] them using a chop saw, when i asked about the heat they all looked at me with the worn out chipmunk look, then said good question, we never thought of that.

RUNT

[geh458]

No mater which cutting implement you use, heat buildup will not be a concern on the chrome moly if you keep the blade lubricated.  I'd worry more about the blade getting too hot, not the tubing.

[fredvance]

When I am cutting something heavy or am concerned about heat, I run water where the blade/wheel is cutting.

[1212FBGS]

so what do ya think creates more heat... cutting the tubing or welding it?....
love ya
Kent

[interested bystander]

Kent, will your quiz be graded?

Hard to beat a chop saw for speed, have used "cold saws" which are slow but . . . COLD as they claim when the cut's done.

Have never had a car crash from a part chop-sawed, but cockpit failure caused a couple.

[38Chevy454]

You are cutting the end and (I presume) going to weld it to something.  The high heat from welding will cause more concern with the metal than the much lower heat from cutting.  Cr-Mo has to be TIG welded because with MIG the heat affected zone will harden and you have a very strong but brittle zone there.  Welding will always mess up whatever the material condition was to start with.  Designers and stress engineers use annealed (weakest) properties for analyzing the strength of any welded joint.

[WhizzbangK.C.]

With chop saws I've always been more concerned about the possibility of the material in the wheel being embedded in the cut and contaminating the joint. Not that I've ever seen anything about it being a problem, but I was taught to file the end lightly while deburring the tube just in case. The heat really shouldn't be a concern, as was pointed out earlier, it gets hotter during welding than the saw gets it.

[manta22]

If you are not cutting a large amount of tubing, try a reciprocating saw. I use a Ryobi (similar to a Sawz-All) with a bi-metal blade and CoolTool cutting fluid. It works just fine and beats the "Armstrong hacksaw" by a mile. I dress the jagged saw cut end on a belt sander using zirconium oxide abrasive-- it lasts longer than the more common aluminum oxide abrasive.

Regards, Neil